Alex Berg chexxor

Lazy/Dynamic Loadable Modules in PureScript

Motivation

https://discourse.purescript.org/t/lazy-loading-routes-in-tea-style-app/141/2

Ideas

Here, we aren't first-class modules, because we are still using the normal module definition and import system. We believe that first-class modules refer to a special feature in OCaml.
Can not refer to type classes across a lazy-load boundary. Type-class instances and classes are not first-class values.

Following is how I would like to define feature development. I hope that by exploring the nature of feature development and its concerns, we can better choose productive constraints to impose on it and better design features such that they can be easily evolved and minimize disruptions to other features.

Feature Architecture

The following are attributes I would like features to have:

A feature in a data management system should be a simple workflow which provides value to a client. A feature's interface should never break active clients, if it has them. A feature can be deployed alongside other features in the same executable, but should be able to be trivially moved out and into a separate executable.

The Elm Architecture is the wrong abstraction for the web

In this article, I'd like to explain why I think The Elm Architecture is fine for small components, but quite harmful for websites based on pages.

Definition and Pros/Cons

First, let's clarify what I mean by "The Elm Architecture".

The Elm Architecture's webpage describes it pretty well.

	Thought you might enjoy reading about the experiences one has on the journey of installing
	Oracle JDeveloper, which is on a whole 'nother level of application installation.
	----
	After reading 4 different documentation sites on Oracle's website and trying three
	different ways to download the JDeveloper installer, I found what seems like the right path.

	The docs for the first JDeveloper installer I found said "Note: if you want to use this
	installer to solve Alex's problems, it will not work. Go to this other doc-site and
	install the JDeveloperQuickInstallerForAlex". Those docs had me download an
	Oracle-custom downloader for this one Oracle thing.


	module Meetup (Weekday(..), Schedule(..), meetupDay) where

	import Data.Time.Calendar --(Day, dayOfWeek, fromGregorian, gregorianMonthLength)
	--import qualified Data.Time.Calendar as Cal
	import Data.List

	data Weekday = Monday
	\| Tuesday
	\| Wednesday

	module Main where

	import Prelude
	import Control.Monad.Eff.Console (log, logShow)
	import TryPureScript (render, withConsole)
	import Control.Lazy (fix)


	-- From https://github.com/awkure/purescript-birds/blob/v1.0.4/src/Aviary/Birds.purs#L38-L38
	fixB :: forall a. (a -> a) -> a

	module Main where

	import Prelude

	import Control.Monad.Eff.Console (log)
	import TryPureScript (render, withConsole)
	import Type.Row


	class HomoHKTRow (rs :: RowList) (f :: Type -> Type)



	newtype WithPipeline a = WithPipeline (NEL.NonEmptyList (a -> a)) a
	-- or --
	newtype WithPipeline a = WithPipeline (a -> a)) a
	instance profunctorWithPipeline :: Profunctor (WithPipeline a) where
	dimap :: forall a b c d. (a -> b) -> (c -> d) -> p b c -> p a d
	dimap a2b c2d (WithPipeline f a) = WithPipeline (a2b >>> f >>> c2d) a
	instance contraWithPipeline :: Contravariant (WithPipeline a) where
	cmap :: forall a b. (b -> a) -> f a -> f b

	module Main where

	import Prelude

	import Control.Monad.Eff (Eff)
	import Control.Monad.Eff.Console (logShow, CONSOLE)
	import Data.Foldable (class Foldable, foldl, intercalate)
	import Data.Maybe (Maybe(..), maybe)
	import Data.Monoid (class Monoid, mempty)
	import Data.StrMap (StrMap, lookup)

	FROM ubuntu

	RUN apt-get update && apt-get -y install wget \
	&& wget https://dl.google.com/cloudsql/cloud_sql_proxy.linux.amd64 \
	&& mv cloud_sql_proxy.linux.amd64 cloud_sql_proxy \
	&& chmod +x cloud_sql_proxy \
	&& mkdir /cloudsql;

	# Expects cred-file.json to be in working directory.
	# This isn't good, but I haven't had time to improve yet.